Idea of the experiment:

(1) Qualitative investigation of [Bi3+] in a systemic

cycle.

(2) Preparation of different [Bi3+] compounds.

(3) Inter-conversion of [Bi3+] compounds.

Systemic Investigation of [Bi3+]

SI - 4

Systemic Investigation of [Bi3+]

SI - 4

Bismuth tetraiodide ion (orange colour)

White ppt. Bismuth hydroxide

(Yellow color)Bismuth triiodide

Exp. 1

Exp. 2

Exp. 3

HNO3

Ag+

Nitrate Salt

(SI-4)Reagents Used:

(1) Acid:

HNO3.: (1:1 solution).

(2) Alkali:NaOH (0.1 M solution).

(3) Salts:

Potassium Iodide.Bismuth nitrate.

Add (1 ml) of sodium hydroxide solution to ca. (2 ml) of Bismuth nitrate.What do you observe?

Exp. 1

Observation:

White ppt. of bismuth hydroxide.

Equation:

3333 2NaNOOHBiNaOH3NOBi

Dissolve the precipitate from experiment (1) in (1 ml) dil. HNO3, and then add (3 ml) of potassium iodide solution to the solution produced from exp.2.What do you observe?

Exp. 2

Observation:

Yellow ppt. of bismuth triiodide.

Equation:

3333 3KNOBiIKI3NOBi

Dissolve the precipitate obtained from exp.2 in excess of KI solution.What do you observe?

Exp. 3

The precipitate dissolves in KI forming orange colour of the complex.

Observation:

Equation: 4BiIKKIBiI3

FinallyDissolve the complex formed from exp.3 in a few drops of conc HNO3. The product is the starting solution of Bismuth nitrate.

FinallyDissolve the complex formed from exp.3 in a few drops of conc HNO3. The product is the starting solution of Bismuth nitrate.

Idea of the experiment:

(1) Qualitative investigation of [Cu++] in a

systemic cycle.

(2) Preparation of different [Cu++] compounds.

(3) Inter-conversion of [Cu++] compounds.

Systemic Investigation of [Cu+

+]

SI - 5

Systemic Investigation of [Cu+

+]

SI - 5

Exp.1Cu++

Exp.2

Exp.3

Nitrate salt

Dark blue solution

Exp.4Bluish white ppt

Copper carbonate

(Pale blue ppt) Copper oxalate HNO3

Blue ppt. Copper hydroxide

(SI - 5)

Reagents Used:

(1) Acid:HCl: (1:1 solution).

(2) Salts:

Sodium oxalate.

Sodium carbonate.

Sodium hydroxide.

Capper nitrate, (5 gm) of the solid dissolved in

(100 ml) of distilled water.

HNO3

(3) Ammonium hydroxide.

Add (1 ml) of sodium oxalate solution to ca. (2 ml) of copper solution.What do you observe?

Exp. 1

Observation:

Pale blue ppt. Of Copper oxalate.Equation:

4O2CCuNaNO2OCNaNOCu 342223

Dissolve the precipitate from experiment (1) in (1ml) NH3 solution.What do you observe?

Exp. 2

Observation:

Dark blue solution.

Add (1 ml) of HCl to the solution produced from exp. 2 and then add (2ml) of Na2CO3.What do you observe?

Exp. 3

Observation:

Bluish white ppt. of CuCO3.Equation:

.OH2CuClHCl2NHCu 22243 OH

.NaCl2CuCOCONaCuCl 3322

Dissolve the precipitate obtained from exp. 3 in (0.5 ml) of HCl and then add few drops of NaOH.What do you observe?

Exp. 4

Observation:Blue ppt. of Cu (OH)2.

Equation:

.NaCl2OHCuNaOH2CuCl 22

FinallyDissolving the Cu(OH)2 precipitate in conc HNO3. The product is the starting solution of copper nitrate.

FinallyDissolving the Cu(OH)2 precipitate in conc HNO3. The product is the starting solution of copper nitrate.

Systemic Investigation of [Hg2+]

SI - 6

Systemic Investigation of [Hg2+]

SI - 6

Idea of the experiment:

(1) Qualitative investigation of [Hg2+] in a systemic

cycle.

(2) Preparation of different [Hg2+] compounds.

(3) Inter-conversion of [Hg2+] compounds.

Reagents Used: (1) Acids:

HCl.

Exp.1

Exp.2

Exp.4 Chloride Salt

Exp.3

Hg2+

Yellow ppt.mercuric oxide

white ppt. amino mercuric

chloride

Red ppt.mercuric iodide

(SI - 6)

(2) Alkali:Sodium hydroxide.Ammonium hydroxide.

Add (1 ml) of NH4 OH to (2 ml) of the mercuric chloride solution.What do you observe?

Exp. 1

Observation:

White ppt. of amino mercuric chloride.

Equation:

(3) Salts:Mercuric chloride.Potassium iodide.

O2HClNHCl2NHHgOHNH2ClHg 2442

Observation:

Yellow ppt. of mercuric oxide.

Equation:

Dissolve the precipitate obtained from experiment (1) in (1-2ml) HCl and then add (2ml) of NaOH.What do you observe?

Exp. 2

OHNaCl2HgONaOH2ClHg 22

Dissolve the precipitate obtained from experiment (2) in (0.5ml) HCl and then add a few drops of KI.What do you observe?

Exp. 3

Equation:

Observation:

Red (initially yellow) precipitate of mercuric iodide.

KCl2HgIKI2ClHg 22

Observation:

The red ppt. dissolves in excess KI and form a complex salt of potassium mercuric-iodide K2[Hg I4].

Add another (2ml) of KI to the precipitate obtained from exp. 3.What do you observe?

Exp. 4

FinallyAddition of a few drops of conc. HCl to the complex obtained from exp. 4, gives the starting solution of mercuric chloride.

FinallyAddition of a few drops of conc. HCl to the complex obtained from exp. 4, gives the starting solution of mercuric chloride.

Equation:

422 IHgKKI2IHg

IF EXP. (II) GIVES NO PRECIPITATE THEN CARRY

OUT EXP. III

IF EXP. (II) GIVES NO PRECIPITATE THEN CARRY

OUT EXP. III

EXPERIMENT. IIIEXPERIMENT. III

To (1ml) of the unknown solution add (2 ml) of ammonium chloride solution and (1 ml) of ammo-nium hydroxide solution

If grey-green ppt. If white gelatinous

ppt.

If reddish brown ppt.

This means that(Cr3+) is present

Carry out (SI - 7) toconfirm this result

This means that(Al3+) is present.

Carry out (SI- 8) toconfirm this result.

This means that(Fe3+) is present.

Carry out (SI- 9) toconfirm this result.

Observation:

Systemic Investigation of [Cr3+]

SI - 7Systemic Investigation of [Cr3+]

SI - 7

Idea of experiment:

(1) Qualitative investigation of [Cr3+] in a systemic

cycle.

(2) Preparation of different [Cr3+] compounds.

(3) Inter-conversion of [Cr3+] compounds.

Reagents Used: (1) Acids:

HCl: (1:1 solution).H2SO4 (1:1 solution).

(2) Alkali:NH4OH (0.1 M solution).NaOH (0.1 M solution).

Exp.1

Cr3+

(Yellow solution.)Cadmium hydroxide

Exp.2

Exp.3

(SI - 7)

(grey green ppt.)Cadmium hydroxide

(3) Salts:Chromium sulfate.Amm. Chloride.Sodium nitrite.

Exp. 1Add (1ml) of the unknown salt solution to (2ml) of ammonium chloride and (1ml) of ammonium hydroxide solution. What do you observe?

Observation:Grey-green ppt. of chromium hydroxide.

Equation:

(4) Hydrogen peroxide, (30%).

423342 SO3NaOHCr2NaOH6)(SOCr

Observation:

The green ppt. dissolves and changed to a yellow solution of chromate.

Exp. 2

Add (2 ml) of sodium hydroxide solution and (1 ml) of hydrogen peroxide solution to the precipitate obtained from experiment (1), and boil.What do you observe?

Equation:

O8H2CrOOH3OH102Cr 2--

4223

Add (1 ml) of H2SO4 and (2 ml) of sodium nitrite solution to the solution obtained from exp. 2 to return to Cr3+ solution again.What do you observe?

Exp. 3

Observation:

The yellow solution of chromate is reduced to the green solution of Cr3+.

Equation:

-33NOO5H2CrNO310HO2Cr 2

3-2

--4